Title :
Spiral antenna NbN hot-electron bolometer mixer at submm frequencies
Author :
Svechnikov, S. ; Gol´tsman, G. ; Voronov, B. ; Yagoubov, P. ; Cherednichenko, S. ; Gershenzon, E. ; Belitsky, V. ; Ekstrom, H. ; Kollberg, E. ; Semenov, A. ; Gousev, Y. ; Renk, K.
Author_Institution :
Dept. of Phys., Moscow State Pedagogical Inst., Russia
fDate :
6/1/1997 12:00:00 AM
Abstract :
We have studied the phonon-cooled hot-electron bolometer (HEB) as a quasioptical mixer based on a spiral antenna designed for the 0.3-1 THz frequency band and fabricated on sapphire and high resistivity silicon substrates. HEB devices were produced from superconducting 3.5-5 nm thick NbN films with a critical temperature 10-12 K and a critical current density of approximately 10/sup 7/ A/cm/sup 2/ at 4.2 K. For these devices we reached a DSB receiver noise temperature below 1500 K, a total conversion loss of L/sub t/=16 dB in the 500-700 GHz frequency range, an IF bandwidth of 3-4 GHz and an optimal LO absorbed power of /spl sime/4 /spl mu/W. We experimentally analyzed various contributions to the conversion loss and obtained an RF coupling factor of about 5 dB, internal mixer loss of 10 dB and IF mismatch of 1 dB.
Keywords :
bolometers; critical current density (superconductivity); electron-phonon interactions; hot carriers; losses; niobium compounds; spiral antennas; submillimetre wave antennas; submillimetre wave mixers; superconducting device noise; superconducting device testing; superconducting microwave devices; superconducting thin films; 0.3 to 1 THz; 10 to 12 K; 16 dB; 3 to 4 GHz; 3.5 to 5 nm; 4 muW; 4.2 K; Al/sub 2/O/sub 3/; DSB receiver noise temperature; IF bandwidth; IF mismatch; NbN; RF coupling factor; Si; critical current density; critical temperature; high resistivity Si substrate; internal mixer loss; mixer chips; optimal LO absorbed power; phonon-cooled hot-electron bolometer; quasioptical mixer; sapphire substrate; spiral antenna NbN hot-electron bolometer mixer; submillimeter frequencies; superconducting NbN films; total conversion loss; Bandwidth; Bolometers; Conductivity; Critical current density; Frequency conversion; Silicon; Spirals; Superconducting device noise; Superconducting films; Temperature distribution;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
